Glycoside derivatives

ABSTRACT

This invention provides a novel compound having a formula such as &lt;IMAGE&gt;  or  &lt;IMAGE&gt;  This invention also provides a process for preparing such a compound. The novel compound has excellent immunological activity.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to glycoside having an excellentimmunological activity and processes for preparation thereof,particularly to N-acetylneuraminic acid derivatives included inglycoside and process for preparation thereof.

(2) Description of the Prior Art

So far, it has been known in the art that N-substituted neuraminic acidsuch as N-acetylneuraminic acids and the like are present in manyanimals and on the cell surface of several bacterias as a complex ofsialic acid such as glycoprotein, glycolipid, oligosaccharide orpolysaccharide.

Recently, N-substituted neuraminic acids have become importantsubstances in medicine and pharmaceutics relative to nerve function,cancer, inflammation, immunity, viral infection, differentiation,hormone receptor etc and have been noted as unique active moleculeslocated on the cell surface. However, the role of N-substitutedneuraminic acids in the complex of sialic acid has not been ascertainedyet.

Furthermore, N-substituted neuraminic acids have been studied by manyorganic chemists and therefore, many kinds of simple derivatives thereofhave been obtained. But no derivative having an excellent immunologicalactivity has been obtained yet.

On the other hand, the average span of human life has been extendedbecause of improvements in medical treatment for malignant tumor ofhematopoietic organ, many kinds of cancers, and collagen disease. On theother hand, with the great increase in use of medicines, for example,medicines for adrenal cortical hormone or immunosuppressant, a number ofundesirable side effects arise together with lowering and decrease inimmunological competence.

SUMMARY OF THE INVENTION

Under such circumstances, the inventors of the present invention havepaid special attention to sialic acid which is a bio-inherent ingredientand they continued their research on control agents for immunity havingfew side effects because of its chemical modification and controleffects for immunological surveillance. As a result of such research,the inventors have succeeded in finding the novel compounds of thepresent invention having immunoregulative effect in which suppressor Tcell is activated and production of immunoglobulin of B cell isrestrained.

The principal object of the present claimed invention is to providenovel compounds having an excellent immunological activity, especiallythe immunoregulation effect.

Another object of this invention is to provide effective processes forpreparing the novel compounds.

These and other objects of this invention are made clear hereunder.

According to the present invention, novel glycoside having the followinggeneral formula (I) are provided. ##STR2## wherein R₁ is selected from##STR3## group, alkoxycarbonyl group, carboxyl group and salts ofcarboxyl group, R₂ is alkoxycarbonyl group, carboxyl group or salts ofcarboxyl group when R₁ is ##STR4## group, R₂ is ##STR5## group when R₁is alkoxycarbonyl group, carboxyl group or salt of carboxyl group, andR₃ is a hydrogen atom or acetyl group.

The alkoxycarbonyl group of the present invention may be exemplified bymethoxycarbonyl group, ethoxycarbonyl group or the like.

The salt of carboxyl group may be exemplified by alkali metal salt oralkali earth metal salt such as sodium salt, potasium salt, calcium saltand the like, of carboxyl group.

The compound (I) of the present invention includes a β configurationderivative (β-derivative) of which R₁ is ##STR6## group and a αconfiguration derivative (α-derivative) of which R₂ is ##STR7## group.

The compound of the present invention represented by the general formula(I) can be prepared by a method shown by the following serial formulasfrom methyl-2-chloro-4,7,8,9-tetra-0-acetyl-β-D-N-acetylneuraminate(hereinafter compound (II)) and5-fluoro-1-[(2-hydroxyethoxy)methyl]uracil (hereinafter compound (III))and obtained as compounds (IV) to (XI). The compounds (IV) to (XI) werenamed as follows:

compound (IV):1-0-[methyl(5-N-acetyl-3,5-dideoxy-4,7,8,9-tetra-0-acetyl-β-D-glycero-D-galacto-5-fluoro-1,2,3,4-tetrahydropyrimidin-1-yl)methy]-ethanediol

compound (V):1-0-[methyl(5-N-acetyl-3,5-dideoxy-4,7,8,9-tetra-0-acetyl-α-D-glycero-D-galacto-2-nonulopyranosyl)onate]-2-0[(2,4-dioxo-5-fluoro-1,2,3,4-tetrahydropyrimidin-1-yl)methyl]-ethanediol

compound (VI):1-0-[methyl(5-N-acetyl-3,5-dideoxy-β-D-glycero-D-galacto-2-nonulopyranosyl)onate]-2-0-[(2,4-dioxo-5-fluoro-1,2,3,4-tetrahydropyrimidin-1-yl)methyl]-ethanediol

compound (VII):1-0-[-methyl(5-N-acetyl-3,5-dideoxy-α-D-glycero-D-galacto-2-nonulopyranosyl)onate]-2-0-[(2,4-dioxo-5-fluoro-1,2,3,4-tetrahydropyrimidin-1-yl)methyl]-ethanediol

compound (VIII):1-0-[-sodium(5-N-acetyl-3,5-dideoxy-βD-glycero-D-galacto-2-nonulopyranosyl)onate]-2-0-[(2,4-dioxo-5-fluoro-1,2,3,4-tetra-hydropyrimidin-1-yl)methyl]-ethanediol

compound (IX):1-0-[sodium(5-N-acetyl-3,5-dideoxy-αD-glycero-D-galacto-2-nonulopyranosyl)onate]2-0-[2,4-dioxo-5-fluoro-1,2,3,4-tetrahydropyrimidin-1-yl)methyl]-ethanediol

compound (X): 1-0-[(5-N-acetyl-3,5-dideoxy-β-D-glycero-D-galacto-2nonulopyranosyl)onicacid]-2-0-[(2,4-dioxo-5-fluoro-1,2,3,4-tetrahydropyrimidin-1-yl)methyl]-ethanediol

compound (XI):1-0-[(5-N-acetyl-3,5-dideoxy-α-D-glycero-D-galacto-2-nonulopyranosyl)onicacid]-2-0-[(2,4-dioxo-5-fluoro-1,2,3,4-tetra-hydropyrimidin-1-yl)methyl]-ethane diol ##STR8##

The compounds (II) and (III) described above are known compounds. Thecompound (II) is synthesized by, for example, a method described inKuhn: Chem. Ber., 99,611 (1966). On the other hand, compound (III) isobtained by, for example, a method described in Morris J. Robins: Can.J. Chem., 60, 547 (1982).

A mixture of novel compounds (IV) (β-derivative) and (V) (α-derivative)is obtained by the Koenigs Knorr reaction of compound (II) and (III).The Koenigs Knorr reaction can be carried out in the presence of HgBr₂,Hg(CN)₂ or a mixture thereof, or in the presence of CF₃ SO₃ Ag (Silvertrifluoromethane sulfonate). The reaction may preferably be carried outin the presence of CF₃ SO₃ Ag because CF₃ SO₃ Ag tends to make the totalyield of the compounds (IV) and (V) higher than HgBr₂ and the like.

Further, said reaction carried out in the presence of CF₃ SO₃ Ag maypreferably be carried out in a solvent such as tetrahydrofuran,acetonitrile, methylene chloride or the like at temperatures of roomtemperature to -50° C. for about 5 to 60 minutes. In particular, it isprefered that the reaction time be about 20 minutes and the solvent betetrahydrofuran. Then novel compounds (IV) (β-devivative and (V)(α-derivative) of the present invention can be separated and purified bysilica gel column chromatography of the product obtained above.

Further, novel compound (VI) (β-derivative) can be obtained bytransesterification of the compound (IV) using sodium methoxyde inmethanol. Similarly, novel compound (VII) (α-derivative) of the presentinvention can be obtained from the compound (V).

Then the compounds (VIII) (β-derivative) and (IX) (α-derivative) can beobtained by hydrolyzing the compounds (VI) and (VII) in a sodiumhydroxide solution. The free acid type compounds (X) (β-derivative) and(XI) (α-derivative) can be obtained by acidifying aqueous solutions ofcompounds (VIII) and (IX) or hydrolyzing the componds (VI) and (VII) ina sodium hydroxide solution and acidfying it.

The preparation method of the present compounds shown by the serialchemical formulas will be shown concretely in the following examples.

According to the present invention, the compounds having the formula (I)have an excellent activity capable of adjusting the strength of theimmune system. Activity capable of adjusting the strength of the immunesystem could be ascertained by the following method.

The function against the activation of mouse spleen lymphocyte by Con A:

As a T cell is non-specifically activated by Con A, glycoside of thepresent invention was added to the reaction and then, the functionthereof was studied. That is, Con A and a compound having the formula(I), for example, the compound prepared in Examples will be shownafterward, were respectively added to the spleen lymphocyte (SPC) whichwas taken from BALB/C mouse and the mixture was cultured for 20 hours orso on the micro plate with 5% CO₂ added to the mixture at 37° C.Thymidine labeled with tritium was added to the mixture obtained andthen SPC was collected further after culturing the mixture at 37° C. for10 hours or so. The amount of ³ H-thymidine taken in SPC was determinedby using a scintillation counter.

Relative to a compound having the formula (I), promotion andreinforcement on ³ H-thymidine taken in was observed, and an improvementin the function against the activation of T-cell by Con A was alsoobserved.

The function against the production of immunoglobulin of mouse spleenlymphocyte:

As for N-substituted neuraminic acid derivatives of the presentinvention which were indicated in the activation of T-cell in theprevious experiment, the function against the production ofimmunoglobulin was studied further by measuring the number ofplaque-forming cells (PFC).

At first, red blood cells of sheep and one of the compounds having theformula (I), for example, the compound prepared in Examples will beshown afterward, was added to SPC and the mixture was cultured at 37° C.for 5 days. SRBC and complement were added again to sensitized SPC thusobtained. The number of PFC was counted after said mixture was culturedin a Cunningham chamber at the temperature of 37° C. for 3 to 12 hours.

Since decrease in the number of PFC was observed and the cell viabilitywas the same as in the control, it was ascertained that repressionagainst production of immunoglobulin was strengthened.

The compounds of the present invention showed an excellent activity inthe two kinds of examination identified above. According to this fact,it was considered that the production of immunoglobulin was repressed byactivating suppressor T cell.

So far, lowering of the function of suppressor T cell has been observedin autoimmune diseases such as collagen disease. Accordingly,N-substituted neuraminic acid derivatives of the present inventionhaving activation function to suppressor T cell are expected to beeffective in clinical applications as an agent for adjusting thestrength of the immune system.

The present invention will now be illustrated by referring to thefollowing nonlimitative examples.

EXAMPLE 1

Preparation method of compounds (IV) and (V):

120 ml of anhydrous tetrahydrofuran solution containing 2.54 g (12.44mmol) of the compound (III) was added with 50 ml anhydrous acetonitrilesolution containing 1.12 g (4.44 mmol) of mercuric cyanide and 2.24 g(6.21 mmol) of mercuric bromide, added 7.74 g of molecular sieves 4Apowder and stirred at room temperature for 1 hour.

Then 35 ml of anhydrous acetonitrile solution containing 4.64 g (9.10mmol) of the compound (II) was added to the resulting mixture obtainedabove and stirred at room temperature for 46 hours.

After the reaction suspension was neutralized with amberlist® A-21 andfiltrated. The resulting filtrate was distilled under reduced pressure,and the residue was dissolved in ethyl acetate, absorbed on 10 g ofsilicagel (Wakogel C-300) and distilled off under reduced pressure thenseparated to a number of fragments by the columnchromatography [solidphase: silicagel (Wakogel C-300) 100 g, eluting solvent:chloroform/methanol=30/1]. Raw materials were recovered from the firstfragment and a mixture of compounds (IV) and (V), object products, wereobtained. After the mixture was separated into fragments by thecolumnchromatography [solid phase: silicagel (Wakogel C-300), elutingsolvent: toluene/methanol=10/1], solvent of two fragments were distilledoff respectively, residue was dissolved in water and subjected to freezedrying. Whereupon 1.82 g (yield: 29.6%) of compound (IV) (β-derivative)and 1.87 g (yield: 30.4%) of compound (V) (α-derivative) were obtainedas pure colorless amorphous crystals. The total yield of compounds (IV)and (V) was 60.0%.

    ______________________________________                                        Physical Properties of compound (IV)                                          ______________________________________                                        Decomposition point                                                                       100-109° C.                                                Elemental analysis                                                                         ##STR9##        MW=688.42                                        Calculation C: 47.11         H: 5.45                                                      N: 6.10                                                           Found       C: 47.15         H: 5.41                                                      N: 5.80                                                           IRν.sup.KBr .sub.max cm.sup.-1 :                                                       3400(NH), 1720(COO)                                                           1670(νCO amide I),                                                         1550(νCO amide II),                                                        1230(COC)                                                         .sup.1 HNMR .sub.400.sup.ppm MHz                                                          (CDCl.sub.3)                                                                  1.894, 2.027, 2.035, 2.063,                                                   2.149 (15H, all S, CH.sub.3 COX5)                                             2.342 (1H, dd, J=13.1Hz, J=4.9Hz,                                             3-Heq)                                                                        3.802 (3H, S, COOCH.sub.3)                                                     ##STR10##                                                                     ##STR11##                                                                    4.780 (1H, d, J=10.7Hz,                                                        ##STR12##                                                                    5.603 (1H, d, J=10.7Hz,                                                        ##STR13##                                                                    5.107-5.174 (1H, m, 4-H)                                                      7.457 (1H, d, J=5.2Hz,                                                        pyrimidine-6-H)                                                   [α] .sub.D.sup.24 - 5.75°                                                    (C=1, AcOEt)                                                      ______________________________________                                        Physical properties of compound (V)                                           ______________________________________                                        Decomposition point                                                                       94-105° C.                                                 Elemental analysis                                                                         ##STR14##       MW=697.43                                        Calculation C: 46.50         H: 5.52                                                      N: 6.03                                                           Found       C: 46.51         H: 5.24                                                      N: 5.90                                                           IRν.sup.KBr .sub.max cm.sup.-1 :                                                       3350 (NH), 1720 (COO),                                                        1670 (νCO, amide I),                                                       1550 (νCO, amide II),                                                      1220 (COC)                                                        .sup.1 HNMR .sub.400.sup.ppm MHz                                                          (CDCl.sub.3)                                                                  1.888, 2.040, 2.148,                                                          2.153 (15H, all S, CH.sub.3 COX5)                                             2.578 (1H, dd, J=12.7Hz, J=4.8Hz,                                             3-Heq)                                                                         ##STR15##                                                                     ##STR16##                                                                     ##STR17##                                                                    5.173 (1H, d, J=10.7Hz                                                         ##STR18##                                                                    5.210 (1H, d, J=10.7Hz                                                         ##STR19##                                                                    4.800-4.903 (1H, m, 4-H)                                                      7.530 (1H, d, J=5.2Hz,                                                        pyrimidine-6-H)                                                   [α] .sub.D.sup.24 - 8.08°                                                    (C=1, AcOEt)                                                      ______________________________________                                    

EXAMPLE 2

Preparation method of compounds (IV) and (V) (2):

70 ml of anhydrous tetrahydrofuran solution containing 1.54 g (7.55mmol) of compound (III) and 2.96 g (5.81 mmol) of compound (II) wasadded with 4.61 g of molecular sieves 4A powder and stirred at roomtemperature for 30 minutes. Then the obtained mixture solution wascooled to -15° to -20° C., added with 8 ml of anhydrous tetrahydroruransolution containing 2.09 g (8.13 mmol) of silver trifuluoromethanesulfonate and stirred for 20 minutes.

After filtration of the reaction suspension obtained and distilling offof the solvent in the resulting filtrate under reduced pressure, residuewas dissolved in 200 ml of ehtyl acetate, washed with water saturatedwith sodium chloride and water saturated sodium hydrogencarbonate anddried with Na₂ SO₄. Then 4.23 g of residue was obtained by filtratingthe drying agent and distilling off the solvent under reduced pressure.4.23 g of the residue was dissolved in ehtyl acetate and separated intofractions by the silicagel chromatography [solid phase: silicagel(Wakogel C-300) 423 g, eluting solvent: toluene/methanol=10/1]. Firstfragment (mixture of raw materials and compound (IV)) and secondfragment (containing compound (V)) were obtained.

After distilling off of a solvent, residue of the first fraction wasseparated to fractions by columnchromatography [solid phase: silicagel(Wakogel C-300), eluting solvent: chloroform/methanol=40/1]. Solvent wasdistilled off from a fragment containing compound (IV), a residue wasdissolved in water and subjected to freeze drying. Whereupon 0.77 g(yield: 19.6%) of compound (IV) (β-derivative) was obtained as a pureproduct. After distilling off of the solvent from the second fragment,the residue was dissolved in water and subjected to freeze drying,whereby 2.70 g (yield: 68.7%) of compound (V) (βderivative) was obtainedas a pure product. The total yield of compounds (IV) and (V) was 88.3%.

EXAMPLE 3

Preparation of compound (VI):

420 mg (0.62 mmol) of compound (IV) obtained in examples 1 and 2 wasdissloved in 100 ml of 0.01N sodium methoxid-methanol solution andstirred at room temperature for 1.5 hours. A reaction solution obtainedwas added with Dowex 50W-X8 H form , neutralized and filtrated. Then theresulting filtrate was concentrated and dried. The residue was subjectedto columnchromatography [solid phase: Silicagel (Wakogel C-200), elutingsolvent: chloroform/methanol=5/3]. The solvent was distilled off from aseparated fragment, and the residue obtained was dissolved in water andsubjected to freeze drying. Whereupon, 270 mg (yield: 86%) of compound(VI) (β-derivative) was obtained as a pure colorless amorphous crystal.

    ______________________________________                                        Physical properties of the product                                            ______________________________________                                        Decomposition point                                                                        138-142° C.                                                Elemental analysis                                                                         ##STR20##       MW = 572.51                                     Calculation  C: 39.86        H: 6.16                                                       N: 7.34                                                          Found        C: 39.62        H: 5.90                                                       N: 7.13                                                          IRν.sup.KBr .sub.max cm.sup.-1 :                                                        3400 (NH, OH),                                                                1710 (COO),                                                                   1670 (νCO amide I),                                                        1560 (νCO amide II)                                           .sup.1 HNMR.sup.ppm .sub.400 MHz                                                           (CDCl.sub.3 + D.sub.2 O)                                                      1.758 (1H, dd, J=12.4Hz,                                                      J=11.9Hz, 3-Hax)                                                               ##STR21##                                                                    2.347 (1H, dd, J=12.4Hz,                                                      J=4.8Hz, 3-Heq)                                                               3.320-4.080 (13H, m, sialyl-H,                                                 ##STR22##                                                                     ##STR23##                                                                    7.940 (1H, d, J=5.4Hz,                                                        pyrimidine-6-H)                                                  [α] .sub.D.sup.19.5 -17.9°                                                    (C=1, DMF)                                                       ______________________________________                                    

EXAMPLE 4

Preparation of compound (VII):

In accordance with the procedure of example 3 but using compound (V)obtained in examples 1 and 2 in place of compound (IV), there wasobtained 221 mg (yield: 80%) of compound (VII) (α-derivative).

    ______________________________________                                        Physical properties of the product                                            ______________________________________                                        Decomposition point                                                                       147-150° C.                                                Elemental analysis                                                                         ##STR24##        MW=543.69                                       Calculation C: 41.97          H: 5.90                                                     N: 7.73                                                           Found       C: 41.77          H: 5.72                                                     N: 7.59                                                           IRν.sup.KBr .sub.max cm.sup.-1 :                                                       3400 (NH, OH),                                                                1710 (COO),                                                                   1670 (νCO, amide I),                                                       1560 (νCO amide II)                                            .sup.1 HNMR .sub.400.sup.ppm MHz                                                          (CDCl.sub.3 + D.sub.2 O)                                                      1.758 (1H, dd, J=12.4Hz,                                                      J=11.1Hz, 3-Hax)                                                               ##STR25##                                                                    2.637 (1H, dd, J=12.4Hz,                                                      J=4.5Hz, 3-Heq)                                                               3.484-3.972 (13H, m,                                                           ##STR26##                                                                     ##STR27##                                                                    7.906 (1H, d, J=5.3Hz,                                                        pyrimidine-6-H)                                                   [α] .sub.D.sup.19.5 - 33.4°                                                  (C=1, DMF)                                                        ______________________________________                                    

EXAMPLE 5

Preparation of compound (VIII):

650 mg (1.28 mmol) of compound (VI) obtained in example 3 was added with2 ml of water and suspended, then added with 2 ml of 1N sodium hydroxideaqueous solution and stirred at room temperature for 20 minutes. Then 1Nsodium hydroxide aqueous solution was added to the obtained mixtureuntil the pH of the reaction mixture was between from 10 and 11 and theresulting mixture was stirred for 5 minutes. The reaction mixture wasadded with Amberlite® IRC-50, adjusted in its pH to between 5 and 6 andfiltrated. Then the obtained filtrate was subjected to freeze drying and636 mg (yield: 96.1%) of compound (VIII) was obtained as a colorlessamorphous crystal.

    ______________________________________                                        Physical properties of the product                                            ______________________________________                                        Decomposition                                                                           196-201° C.                                                  point                                                                         Elemental analysis                                                                       ##STR28##          MW = 567.86                                     Calculation                                                                             C: 38.07           H: 5.43                                                    N: 7.40                                                             Found     C: 37.80           H: 5.25                                                    N: 7.20                                                             IRν.sup.KBr .sub.max cm.sup.-1 :                                                        3400 (NH, OH),                                                                1700, 1670 (νCO amide I),                                                  1610 (COO.sup.⊖),                                                     1560 (νCO amide II).                                          [α] .sub.D.sup.19.5 -15.5°                                                    (C=1, H.sub.2 O)                                                 .sup.1 HNMR.sup.ppm .sub.400 MHz                                                           (DMSO-d.sub.6, t-BuOH)                                                        1.465 (1H, t, J=11.9Hz, 3-Hax)                                                1.871 (3H, S, CH.sub.3 CONH)                                                  2.083 (1H, dd, J=11.9Hz, 4.5Hz, 3-Heq)                                        3.331-3.669                                                                   (10H, m, sialyl-H,                                                            OCH.sub.2 CH.sub.2O)                                                          3.808 (1H, m, 4H)                                                             5.052 (1H, d, J=10.3Hz,                                                        ##STR29##                                                                    5.090 (1H, d, J=10.3Hz,                                                        ##STR30##                                                                    5.276 (1H, OH)                                                                8.113 (1H, s, J=6.6Hz, primidine-6'H)                                         8.245 (1H, d, J=7.3Hz, CH.sub.3 CONH)                            ______________________________________                                    

EXAMPLE 6

Preparation of compound (IX):

In accordance with the procedure of example 5 but using 372 mg (0.73mmol) of compound (VII) obtained in example (4) in place of compound(VI) and using 1.5 ml of 1 N sodium hydroxide aqueous solution, 373 mg(yield: 98.6%) of compound (IX) was obtained.

    ______________________________________                                        Physical properties of the product                                            ______________________________________                                        Decomposition point                                                                        178-183° C.                                               Elemental analysis                                                                         C.sub.18 H.sub.25 FN.sub.3 NaO.sub.12.4H.sub.2 O                                              MW = 589.48                                      Calculation  C: 36.68        H: 5.64                                                       N: 7.13                                                          Found        C: 36.39        H: 5.51                                                       N: 6.95                                                          IRν.sup.KBr .sub.max cm.sup.-1 :                                                        3400 (NH, OH),                                                                1700, 1670 (νCO amide I)                                                   1610 (COO.sup.⊖),                                                     1560 (νCO, amide II)                                          [α] .sub.D.sup.19.5 -4.5°                                                     (C=1, H.sub.2 O)                                                 .sup.1 HNMR.sup.ppm .sub.400 Hz                                                            (DMSO-d.sub.6, t-BuOH)                                                        1.242 (1H, t, J=11.7Hz, 3-Hax)                                                1.888 (3H, S, CH.sub.3 CONH)                                                  2.650 (1H, dd, J=11.7Hz,                                                      4.6Hz, 3-Heq)                                                                 3.18-3.58 (10H, m, sialyl-H,                                                  OCH.sub.2 CH.sub.2O)                                                          3.725 (1H, m, 4-H)                                                            4.793 (1H, m, OH)                                                              ##STR31##                                                                    5.235 (1H, S, OH)                                                             6.338 (1H, S, OH)                                                             8.118 (2H, d, J=6.4Hz, Pyrimidine-6'H)                                         ##STR32##                                                       ______________________________________                                    

EXAMPLE 7

Preparation of compound (X) (1):

A solution of 100 mg (1.28 mmol) of compound (VIII) obtained in example5 and 30 ml of distilled water was added with about 3 ml of Dowex 50W-X8(H form) and stirred at room temperature for 1 hour. The pH of theresulting solution was 4.

The filtrate obtained by filtrating the reaction mixture was subjectedto freeze drying and there was obtained 84 mg (yield: 89.2%) of compound(X) as a colorless amorphous crystal.

    ______________________________________                                        Physical properties of the product                                            ______________________________________                                        Decomposition point                                                                       138-148° C.                                                Elemental analysis                                                                         ##STR33##        MW=515.25                                       Calculation C: 41.96          H: 5.52                                                     N: 8.16                                                           Found       C: 41.70          H: 5.20                                                     N: 8.08                                                           IRν.sup.KBr .sub.max cm.sup.-1 :                                                       3400 (OH, NH),                                                                1700 (COOH), 1680 (NHCO)                                          .sup.1 HNMR .sub.400.sup.ppm MHz                                                          (DMSOd.sub.6)                                                                 1.620 (1H, t, J=12.5Hz, 3-Hax),                                                ##STR34##                                                                    2.257 (1H, dd, J=12.5Hz,                                                      4.5Hz, 3-Heq)                                                                 3.90-3.89 (1H, m, 4-H),                                                        ##STR35##                                                                    7.972 (1H, d, J=6.0Hz,                                                        pyrimidine-6'H)                                                   [α] .sub.D.sup.19.5 - 16.8°                                                  (C=1, H.sub.2 O)                                                  ______________________________________                                    

EXAMPLE 8

Preparation of compound (XI) (1):

In accordance with the procedure of example 7 but using 102 mg (0.20mmol) of compound (IX) obtained in example 6 in place of compound(VIII), there was obtained 90.4 mg (yield: 92.4%) of compound (XI).

    ______________________________________                                        Physical properties of the compound (XI)                                      ______________________________________                                        Decomposition point                                                                        123-128° C.                                               Elemental analysis                                                                         C.sub.18 H.sub.26 FN.sub.3 O.sub.12.H.sub.2 O                                                 MW=513.45                                        Calculation  C: 42.11        H: 3.70                                                       N: 8.18                                                          Found        C: 41.85        H: 3.41                                                       N: 8.10                                                          IRν.sup.KBr .sub.max cm.sup.-1 :                                                        3400 (OH, NH),                                                                1700 (COOH), 1680 (NHCO),                                        .sup.1 HNMR .sub.400.sup.ppm MHz                                                           (DMSOd.sub.6),                                                                1.572 (1H, t, J=12.2Hz, 3-Hax),                                                ##STR36##                                                                    2.655 (1H, dd, J=12.2Hz,                                                      4.5Hz, 3-Heq),                                                                3.82-3.90 (1H, m, 4-H),                                                        ##STR37##                                                                    7.975 (1H, d, J=6.0Hz,                                                        pyrimidine-6'H)                                                  [α] .sub.D.sup.19.5 - 5.8°                                                    (C=1, H.sub.2 O)                                                 ______________________________________                                    

EXAMPLE 9

Preparation of compound (X) (2):

100 mg (0.196 mmol) of compound (VI) obtained in example 3 was dissolvedin 2 ml of water and added with 0.2 ml of 1 N sodium hydroxide aqueoussolution. After agitating at room temperature for 3 hours, the reactionmixture was added with Dowex 50W-X8 (H type), stirred for about 30minutes, filtrated and washed with water. The filtrate and the washingsolution were subjected to freeze drying and there was obtained 90 mg(yield: 93%) of the compound (X).

EXAMPLE b 10

Preparation of compound (XI) (2):

In accordance with the precedure of example 9 but using compound (VII)obtained in example 4 in place of compound (VI), 88 mg (yield: 91%) ofcompound (XI) was obtained.

We claim:
 1. A glycoside having the formula: ##STR38## wherein R₁ isselected from the group consisting of ##STR39## , methoxycarbonylethoxycarbonyl, the carboxyl group and the sodium, potassium or calciumsalt of the carboxyl group: R₂ is methoxycarbonyl, ethoxycarbonyl, thecarboxyl group or the salt of the carboxyl group when R₁ is ##STR40## R₂is ##STR41## when R₁ is ##STR42## methoxycarbonyl, ethoxycarbonyl, thecarboxyl group or the sodium, potassium or calcium salt of the carboxylgroup; and R₃ is hydrogen or acetyl.
 2. The glycoside of claim 1,wherein R₁ is ##STR43## and R₂ is methoxycarbonyl, ethoxycarbonyl, thecarboxyl group or the sodium, potassium or calcium salt of the carboxylgroup.
 3. The glycoside of claim 1, wherein R₁ is methoxcarbonyl,ethoxycarbonyl, the carboxyl group or the sodium, potassium or calciumsalt of the carboxyl group and R₂ is ##STR44##
 4. The glycoside of claim1, wherein the alkoxycarbonyl group is methoxycarbonyl.